By classical definition, the term "dry cleaning" has been used to describe processes for cleaning textiles using nonaqueous solvents. Dry cleaning is an old art, with solvent cleaning first being recorded in the United Kingdom in the 1860's. Typically, dry cleaning processes are used with garments such as woolens which are subject to shrinkage in aqueous laundering baths, or which are judged to be too valuable or too delicate to subject to aqueous laundering processes. Various hydrocarbon and halocarbon solvents have traditionally been used in immersion dry cleaning processes, and the need to handle and reclaim such solvents has mainly restricted the practice of conventional dry cleaning to commercial establishments.
While solvent-based dry cleaning processes are quite effective for removing oily soils and stains, they are not optimal for removing particulates such as clay soils, and may require special treatment conditions to remove proteinaceous stains. Ideally, particulates and proteinaceous stains are removed from fabrics using detersive ingredients and operating conditions which are more akin to aqueous laundering processes than to conventional dry cleaning.
In addition to the cleaning function, conventional dry cleaning processes also provide important "refreshment" benefits. For example, dry cleaning removes undesirable odors and extraneous matter such as hair and lint from garments, which are then generally folded or pressed to remove wrinkles and restore their original shape. Of course, such refreshment benefits are also afforded by aqueous laundering processes.
As can be seen from the foregoing, and aside from the effects on certain fabrics such as woolens, there are no special, inherent advantages for solvent-based immersion dry cleaning over aqueous cleaning processes with respect to fabric cleaning or refreshment. Moreover, on a per-garment basis, commercial dry cleaning is much more expensive than aqueous cleaning processes. Accordingly, it would be of considerable benefit to consumers to provide non-immersion processes for cleaning "dry-clean only" fabrics which can be used in the home.
One type of home cleaning system comprises a carrier sheet containing various cleaning agents, and a plastic bag. The garments to be cleaned are placed in the bag together with the sheet, and then tumbled in a conventional clothes dryer. In a commercial embodiment, multiple single-use flat sheets and a single multi-use plastic bag are provided in a package. Unfortunately, such processes may not satisfactorily remove stains from heavily soiled or "spotted" areas of the fabrics being dry cleaned.
As is well known, heavily stained garments may be "pre-spotted" using so-called "spot removal" compositions prior to cleaning. Improved spot-removal procedures use devices which allow the user to pre-spot fabrics without resort to rubbing, thereby minimizing fabric damage. Such devices are designed to work in concert with pre-spotting compositions to loosen and remove stains via controlled mechanical action, thereby avoiding fabric damage. Briefly stated, such devices are designed to gently implement Z-axis mechanics only, with respect to the fabric being treated. Indeed, preferred devices actually promote Z-axis mechanics and dissuade the user from employing an undesirable side-to-side rubbing motion.
However, it has now been discovered that, even when using preferred cleaning devices in combination with pre-spotting compositions, some spots and stains may not be removed from the fabrics in optimal fashion. This is especially true in home-use cleaning, wherein the operator has had no special training in the spot removal operation. For example, certain food stains such as spaghetti sauce, ketchup, coffee, tea, wine, and the like, contain color bodies which may be incompletely removed from the fabric by conventional pre-spotting compositions. By the present invention it has been discovered that the use of a peroxide bleach, especially hydrogen peroxide, preferably in combination with solvents and a major proportion of water, and most preferably with a chelating agent, efficiently and effectively removes such stains.